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40 results on '"Marquis, Mélanie"'

11. Droplet microfluidics for food and nutrition applications

Author

Schroen, Karin, Berton-Carabin, Claire, Renard, Denis, Marquis, Mélanie, Boire, Adeline, Cochereau, Rémy, Amine, Chloé, Marze, Sébastien, Schroen, Karin, Berton-Carabin, Claire, Renard, Denis, Marquis, Mélanie, Boire, Adeline, Cochereau, Rémy, Amine, Chloé, and Marze, Sébastien

Abstract

Droplet microfluidics revolutionizes the way experiments and analyses are conducted in many fields of science, based on decades of basic research. Applied sciences are also impacted, opening new perspectives on how we look at complex matter. In particular, food and nutritional sciences still have many research questions unsolved, and conventional laboratory methods are not always suitable to answer them. In this review, we present how microfluidics have been used in these fields to produce and investigate various droplet-based systems, namely simple and double emulsions, microgels, microparticles, and microcapsules with food-grade compositions. We show that droplet microfluidic devices enable unprecedented control over their production and properties, and can be integrated in lab-on-chip platforms for in situ and time-resolved analyses. This approach is illustrated for on-chip measurements of droplet interfacial properties, droplet–droplet coalescence, phase behavior of biopolymer mixtures, and reaction kinetics related to food digestion and nutrient absorption. As a perspective, we present promising developments in the adjacent fields of biochemistry and microbiology, as well as advanced microfluidics–analytical instrument coupling, all of which could be applied to solve research questions at the interface of food and nutritional sciences.

Published
2021

13. Microcarriers Based on Glycosaminoglycan-Like Marine Exopolysaccharide for TGF-beta1 Long-Term Protection

Author

Zykwinska, Agata, Marquis, Mélanie, Godin, Mathilde, Marchand, Laëtitia, Sinquin, Corinne, Garnier, Catherine, Jonchère, Camille, Chédeville, Claire, Le Visage, Catherine, Guicheux, Jérôme, Colliec-Jouault, Sylvia, Cuenot, Stéphane, Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies [IFREMER, Nantes], Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Centre de Recherche Épidémiologie et Statistique Sorbonne Paris Cité (CRESS (U1153 / UMR_A_1125 / UMR_S_1153)), Université Paris Diderot - Paris 7 (UPD7)-Université Sorbonne Paris Cité (USPC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de la Recherche Agronomique (INRA), Regenerative Medicine and Skeleton research lab (RMeS), Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Nantes - UFR Odontologie, Université de Nantes (UN), Ostéo-articulaire - Tête et cou - Odontologie - Neurochirurgie - Neurotraumatologie [CHU Nantes] (Pôle hospitalo-universitaire PHU4 - OTONN), Centre hospitalier universitaire de Nantes (CHU Nantes), Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de la Recherche Agronomique (INRA)-Université Paris Descartes - Paris 5 (UPD5)-Université Sorbonne Paris Cité (USPC), Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), UFR d’Odontologie [CHU Hôtel Dieu, Nantes], Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Ecosystèmes microbiens et Molécules Marines pour les Biotechnologies (EM3B), Biotechnologies et Ressources Marines (BRM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut National de la Recherche Agronomique (INRA)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Regenerative Medicine and Skeleton (RMeS), École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), Université de Nantes (UN)-Université de Nantes (UN)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Jehan, Frederic

Subjects
Cartilage, Articular, Drug Compounding, microfluidics, Biological Availability, Article, Cell Line, Transforming Growth Factor beta1, Hydrothermal Vents, Polysaccharides, Humans, Regeneration, lcsh:QH301-705.5, Drug Implants, microparticles, Drug Carriers, [SDV.MHEP.RSOA] Life Sciences [q-bio]/Human health and pathology/Rhumatology and musculoskeletal system, Tissue Scaffolds, [SDV.MHEP.GEG] Life Sciences [q-bio]/Human health and pathology/Geriatry and gerontology, [SDV.MHEP.GEG]Life Sciences [q-bio]/Human health and pathology/Geriatry and gerontology, growth factor, Drug Liberation, lcsh:Biology (General), [SDV.MHEP.RSOA]Life Sciences [q-bio]/Human health and pathology/Rhumatology and musculoskeletal system, bioactivity, Delayed-Action Preparations, exopolysaccharide, Alteromonas
Abstract

Articular cartilage is an avascular, non-innervated connective tissue with limited ability to regenerate. Articular degenerative processes arising from trauma, inflammation or due to aging are thus irreversible and may induce the loss of the joint function. To repair cartilaginous defects, tissue engineering approaches are under intense development. Association of cells and signalling proteins, such as growth factors, with biocompatible hydrogel matrix may lead to the regeneration of the healthy tissue. One current strategy to enhance both growth factor bioactivity and bioavailability is based on the delivery of these signalling proteins in microcarriers. In this context, the aim of the present study was to develop microcarriers by encapsulating Transforming Growth Factor-&beta, 1 (TGF-&beta, 1) into microparticles based on marine exopolysaccharide (EPS), namely GY785 EPS, for further applications in cartilage engineering. Using a capillary microfluidic approach, two microcarriers were prepared. The growth factor was either encapsulated directly within the microparticles based on slightly sulphated derivative or complexed firstly with the highly sulphated derivative before being incorporated within the microparticles. TGF-&beta, 1 release, studied under in vitro model conditions, revealed that the majority of the growth factor was retained inside the microparticles. Bioactivity of released TGF-&beta, 1 was particularly enhanced in the presence of highly sulphated derivative. It comes out from this study that GY785 EPS based microcarriers may constitute TGF-&beta, 1 reservoirs spatially retaining the growth factor for a variety of tissue engineering applications and in particular cartilage regeneration, where the growth factor needs to remain in the target location long enough to induce robust regenerative responses.

Published
2019

14. Microcarriers based on glycosaminoglycan-like marine exopolysaccharide for TGF-β1 long-term protection

Author

Marquis, Mélanie, Godin, Mathilde, Marchand, Laëtitia, Sinquin, Corinne, Garnier, Catherine, Jonchere, Camille, Chédeville, Claire, Le Visage, Catherine, Guicheux, Jérome, Colliec-Jouault, Sylvia, Cuenot, Stéphanie, and Zykwinska, Agata

Subjects
exopolysaccharide, growth factor, microparticles, microfluidics, bioactivity
Abstract

Articular cartilage is an avascular, non-innervated connective tissue with limited ability to regenerate. Articular degenerative processes arising from trauma, inflammation or due to aging are thus irreversible and may induce the loss of the joint function. To repair cartilaginous defects, tissue engineering approaches are under intense development. Association of cells and signalling proteins, such as growth factors, with biocompatible hydrogel matrix may lead to the regeneration of the healthy tissue. One current strategy to enhance both growth factor bioactivity and bioavailability is based on the delivery of these signalling proteins in microcarriers. In this context, the aim of the present study was to develop microcarriers by encapsulating Transforming Growth Factor-β1 (TGF-β1) into microparticles based on marine exopolysaccharide (EPS), namely GY785 EPS, for further applications in cartilage engineering. Using a capillary microfluidic approach, two microcarriers were prepared. The growth factor was either encapsulated directly within the microparticles based on slightly sulphated derivative or complexed firstly with the highly sulphated derivative before being incorporated within the microparticles. TGF-β1 release, studied under in vitro model conditions, revealed that the majority of the growth factor was retained inside the microparticles. Bioactivity of released TGF-β1 was particularly enhanced in the presence of highly sulphated derivative. It comes out from this study that GY785 EPS based microcarriers may constitute TGF-β1 reservoirs spatially retaining the growth factor for a variety of tissue engineering applications and in particular cartilage regeneration, where the growth factor needs to remain in the target location long enough to induce robust regenerative responses.

Published
2019

15. Microcarriers Based on Glycosaminoglycan-Like Marine Exopolysaccharide for TGF-β1 Long-Term Protection

Author

Zykwinska, Agata, primary, Marquis, Mélanie, additional, Godin, Mathilde, additional, Marchand, Laëtitia, additional, Sinquin, Corinne, additional, Garnier, Catherine, additional, Jonchère, Camille, additional, Chédeville, Claire, additional, Le Visage, Catherine, additional, Guicheux, Jérôme, additional, Colliec-Jouault, Sylvia, additional, and Cuenot, Stéphane, additional

Published
2019
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16. Mesenchymal stem cell encapsulation in alginate micro-particles for intra-articular injection in osteoarthritis

Author

Smith, A., Boulestreau, J., Marquis, Mélanie, Renard, Denis, Legoff, B., Blanchard, F., Vinatier, C., Guicheux, J., Des Rieux, A., Le Visage, C., Institut National de la Santé et de la Recherche Médicale (INSERM), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Université Catholique de Louvain = Catholic University of Louvain (UCL), and ProdInra, Migration

Subjects
030203 arthritis & rheumatology, 0303 health sciences, 03 medical and health sciences, [SDV.MHEP] Life Sciences [q-bio]/Human health and pathology, 0302 clinical medicine, Rheumatology, Biomedical Engineering, Orthopedics and Sports Medicine, ComputingMilieux_MISCELLANEOUS, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology, 3. Good health, 030304 developmental biology
Abstract

International audience

Published
2019

17. Microfluidic lab-on-chip devices to generate and trap monodisperse micro-sized oil droplets for digestion study

Author

NGUYEN, Hoang Thanh, Marquis, Mélanie, MARZE, SEBASTIEN, ProdInra, Migration, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), and University of Electronic Science and Technology of China (UESTC). CHN.

Subjects
[SPI.GPROC] Engineering Sciences [physics]/Chemical and Process Engineering, [SDV.IDA]Life Sciences [q-bio]/Food engineering, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, [SDV.IDA] Life Sciences [q-bio]/Food engineering, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

18. Oil core microcapsules by alginate inverse gelation technique

Author

Martins, Evandro, Renard, Denis, Davy, Joëlle, Marquis, Mélanie, Poncelet, Denis, Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), and Institut National de la Recherche Agronomique (INRA)

Subjects
emulsion, [CHIM.POLY]Chemical Sciences/Polymers, optimisation, alginate, mixing, encapsulation
Abstract

A promising technique for oil encapsulation in Ca-alginate capsules by inverse gelation was proposed by Abang et al. This method consists of emulsifying calcium chloride solution in oil and then adding it dropwise in an alginate solution to produce Ca-alginate capsules. Spherical capsules with diameters around 3 mm were produced by this technique, however the production of smaller capsules was not demonstrated. The objective of this study is to propose a new method of oil encapsulation in a Ca-alginate membrane by inverse gelation. The optimisation of the method leads to microcapsules with diameters around 500 mm. In a search of microcapsules with improved diffusion characteristics, the size reduction is an essential factor to broaden the applications in food, cosmetics and pharmaceuticals areas. This work contributes to a better understanding of the inverse gelation technique and allows the production of microcapsules with a well-defined shell-core structure.

Published
2015

19. Mimicking the gastrointestinal digestion in a lab-on-a-chip:the microdigester

Author

Marze, Sebastien, Marquis, Mélanie, ProdInra, Migration, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), and Superviseur : Monique Axelos

Subjects
[SDV.AEN] Life Sciences [q-bio]/Food and Nutrition, [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition
Abstract

By combining food and miniaturization knowledge, INRA researchers in UR BIA (Nantes, France) designed a lab-on-a-chip dedicated to gastrointestinal digestion studies at the micrometer scale. This device has already been used to monitor the digestion of lipid droplets in the presence of proteins. A real-time microscopy analysis provided similar results compared to those obtained in a test tube, but was much faster since it did not require further titrations on samples. This system opens up new prospects for studying the digestion of micronutrients., En mettant en commun les connaissances de la digestion des aliments et de la miniaturisation des écoulements, les chercheurs de l'INRA de Nantes ont conçu un laboratoire sur une puce dédiée à l'étude de la digestion gastro-intestinale à l'échelle du micromètre (microdigesteur). Cet outil d'ores et déjà été utilisé pour suivre la digestion des lipides sous forme de gouttes en présence de protéines. Une analyse par microscopie en temps réel fourni des résultats similaires par rapport à ceux obtenus en éprouvette, mais beaucoup plus rapidement car ne nécessitant pas de dosages sur échantillons prélevés . Ce système ouvre des perspectives pour étudier la digestion des micronutriments .

Published
2015

20. Biofunctional microassemblies on an exopolysaccharide produced by a deep sea hydrothermal bacterium for tissue engineering applications

Author

Zykwinska, Agata, Marquis, Mélanie, Davy, Joëlle, Sinquin, C., Ratiskol, J., Cuenot, S., Renard, Denis, Colliec-Jouault, S., Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER). Nantes, FRA., and ProdInra, Migration

Subjects
[SDV.IB.BIO] Life Sciences [q-bio]/Bioengineering/Biomaterials, Biopolymer, Microfluidic, [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SDV.IB.BIO]Life Sciences [q-bio]/Bioengineering/Biomaterials, ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2014

21. Tuning optical properties of cellulose nanofibrils-based multilayered thin films

Author

Azzam, Firas, Moreau, Céline, Marquis, Mélanie, Bizot, Herve, Cousin, F., Cathala, Bernard, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), American Chemical Society (ACS). USA., and ProdInra, Migration

Subjects
[SPI.GPROC] Engineering Sciences [physics]/Chemical and Process Engineering, [SDV.IDA]Life Sciences [q-bio]/Food engineering, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, [SDV.IDA] Life Sciences [q-bio]/Food engineering, ComputingMilieux_MISCELLANEOUS
Abstract

Dallas, TX 0; International audience

Published
2014

24. Contrôle de taille et de forme de microgels à base de biopolymères générés par microfluidique

Author

Marquis, Mélanie, Davy, Joëlle, Fang, Aiping, Renard, Denis, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Groupe Français d’Etudes et d’Applications des Polymères. FRA. Société Française de Génie des Procédés (SFGP), FRA., and ProdInra, Migration

Subjects
[CHIM.POLY] Chemical Sciences/Polymers, Shrinking, [CHIM.POLY]Chemical Sciences/Polymers, polysaccharide, microfluidique, pectine
Published
2013

25. Generation of innovative biopolymer-based microbeads by microfluidic tools

Author

Marquis, Mélanie, Davy, Joëlle, Cathala, Bernard, Fang, Aiping, Renard, Denis, ProdInra, Migration, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Université de Bordeaux (UB). Bordeaux, FRA. Centre National de la Recherche Scientifique (CNRS)., and Institut National de Recherche Agronomique (INRA). UR Biopolymères, Interactions Assemblages (1268).

Subjects
[SDV.AEN] Life Sciences [q-bio]/Food and Nutrition, [SDV.IDA]Life Sciences [q-bio]/Food engineering, [SDV.IDA] Life Sciences [q-bio]/Food engineering, [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition
Published
2013

27. Biopolymer-Based Janus Hydrogels: Microfluidic Production and Selective Degradations

Author

Marquis, Mélanie, Renard, Denis, Valcourt, Chantal, Cathala, Bernard, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Université des Sciences et Technologies (Bordeaux 1). Talence, FRA., and ProdInra, Migration

Subjects
[CHIM.POLY] Chemical Sciences/Polymers, [CHIM.POLY]Chemical Sciences/Polymers, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, [CHIM.ORGA]Chemical Sciences/Organic chemistry, [CHIM.ORGA] Chemical Sciences/Organic chemistry, [SDV.BIO] Life Sciences [q-bio]/Biotechnology
Published
2012

28. Novel functional biopolymer-based microbeads

Author

Marquis, Mélanie, Renard, Denis, Cathala, Bernard, ProdInra, Migration, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), and Institut National de la Recherche Agronomique (INRA)

Subjects
[CHIM.POLY] Chemical Sciences/Polymers, [CHIM.POLY]Chemical Sciences/Polymers, beads, Microfluidics, polysaccharides
Published
2011

36. Cell Wall Modifications in Arabidopsis Plants with Altered α-l-Arabinofuranosidase Activity

Author

Chávez Montes, Ricardo A., primary, Ranocha, Philippe, additional, Martinez, Yves, additional, Minic, Zoran, additional, Jouanin, Lise, additional, Marquis, Mélanie, additional, Saulnier, Luc, additional, Fulton, Lynette M., additional, Cobbett, Christopher S., additional, Bitton, Frédérique, additional, Renou, Jean-Pierre, additional, Jauneau, Alain, additional, and Goffner, Deborah, additional

Published
2008
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37. Oil core microcapsules by inverse gelation technique.

Author

Martins, Evandro, Renard, Denis, Davy, Joëlle, Marquis, Mélanie, and Poncelet, Denis

Subjects
MOLECULAR capsules, MICROENCAPSULATION, STABILIZING agents, FOOD emulsifiers, GELATION
Abstract

A promising technique for oil encapsulation in Ca-alginate capsules by inverse gelation was proposed by Abang et al. This method consists of emulsifying calcium chloride solution in oil and then adding it dropwise in an alginate solution to produce Ca-alginate capsules. Spherical capsules with diameters around 3 mm were produced by this technique, however the production of smaller capsules was not demonstrated. The objective of this study is to propose a new method of oil encapsulation in a Ca-alginate membrane by inverse gelation. The optimisation of the method leads to microcapsules with diameters around 500 μm. In a search of microcapsules with improved diffusion characteristics, the size reduction is an essential factor to broaden the applications in food, cosmetics and pharmaceuticals areas. This work contributes to a better understanding of the inverse gelation technique and allows the production of microcapsules with a well-defined shell-core structure. [ABSTRACT FROM AUTHOR]

Published
2015
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39. A microfluidic device to study the digestion of trapped lipid droplets.

Author

Marze S, Algaba H, and Marquis M

Subjects
Emulsions chemistry, Microfluidic Analytical Techniques methods, Models, Biological, Triglycerides chemistry, Digestion, Lipid Droplets chemistry, Microfluidic Analytical Techniques instrumentation
Abstract

At the junction of chemistry, physics and biology, digestion involves many processes. Studying the mechanisms in such a complex system is challenging because numerous interactions coexist. Even in an apparently simple system such as an emulsion, many physicochemical characteristics affect lipid digestion. Moreover, these characteristics are difficult to control using conventional in vitro techniques. The goal of this work was to design a microfluidic device allowing the study of well-controlled individual oil droplets under gastrointestinal digestion conditions. Different parameters were investigated in order to validate the relevance of this device compared to conventional in vitro techniques using emulsions. Various triglycerides and digestion conditions were tested with droplets of the same initial diameter generated by a flow focusing device, then placed in individual traps of a microfluidic chamber for digestion with continuous digestive juice renewal. The results are in good agreement with those obtained with conventional in vitro techniques and open the way to screening of lipid digestion, in particular, bioaccessibility of lipophilic molecules, a prerequisite for bioavailability studied in nutrition, pharmacology, and toxicology.

Published
2014
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40. Cell wall modifications in Arabidopsis plants with altered alpha-L-arabinofuranosidase activity.

Author

Chávez Montes RA, Ranocha P, Martinez Y, Minic Z, Jouanin L, Marquis M, Saulnier L, Fulton LM, Cobbett CS, Bitton F, Renou JP, Jauneau A, and Goffner D

Subjects
Arabidopsis genetics, Arabidopsis growth & development, DNA, Bacterial, Gene Expression, Gene Expression Profiling, Glucuronidase metabolism, Immunohistochemistry, Monosaccharides metabolism, Mutagenesis, Insertional, Oligonucleotide Array Sequence Analysis, Phenotype, Plant Stems growth & development, Arabidopsis enzymology, Arabidopsis Proteins metabolism, Cell Wall metabolism, Polysaccharides metabolism, Xylosidases metabolism
Abstract

Although cell wall remodeling is an essential feature of plant growth and development, the underlying molecular mechanisms are poorly understood. This work describes the characterization of Arabidopsis (Arabidopsis thaliana) plants with altered expression of ARAF1, a bifunctional alpha-L-arabinofuranosidase/beta-D-xylosidase (At3g10740) belonging to family 51 glycosyl-hydrolases. ARAF1 was localized in several cell types in the vascular system of roots and stems, including xylem vessels and parenchyma cells surrounding the vessels, the cambium, and the phloem. araf1 T-DNA insertional mutants showed no visible phenotype, whereas transgenic plants that overexpressed ARAF1 exhibited a delay in inflorescence emergence and altered stem architecture. Although global monosaccharide analysis indicated only slight differences in cell wall composition in both mutant and overexpressing lines, immunolocalization experiments using anti-arabinan (LM6) and anti-xylan (LM10) antibodies indicated cell type-specific alterations in cell wall structure. In araf1 mutants, an increase in LM6 signal intensity was observed in the phloem, cambium, and xylem parenchyma in stems and roots, largely coinciding with ARAF1 expression sites. The ectopic overexpression of ARAF1 resulted in an increase in LM10 labeling in the secondary walls of interfascicular fibers and xylem vessels. The combined ARAF1 gene expression and immunolocalization studies suggest that arabinan-containing pectins are potential in vivo substrates of ARAF1 in Arabidopsis.

Published
2008
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